Atomic Theory and Subatomic Particles: Key Concepts Explained
Key Concepts in Atomic Theory
Which of the following was one of Dalton’s improvements over Democritus’s ideas?
Atoms retain their identity in a chemical reaction.
Dalton’s Atomic Theory
Atoms of the same element are always identical.
Which discovery did J. J. Thomson make that improved upon Dalton’s atomic theory?
Atoms contain tiny, negatively charged electrons
Which of the following was originally a tenet of Dalton’s atomic theory, but had to be revised about a century ago?
Atoms are tiny indivisible
Read MorePharmaceutical Emulsions: Types, Preparation, and Stability
Pharmaceutical Emulsions
Emulsions are dispersion systems consisting of at least two immiscible fluids, or semi-solid easy-melting substances, one of which is dispersed throughout the other in the form of fine droplets. The diameter of these droplets is usually bigger than 0.5 µm. Pharmaceutical emulsions usually consist of water and oil.
Types of Emulsions
Two main basic types of emulsion can exist: oil-in-water (o/w) and water-in-oil (w/o), depending upon whether the continuous (outer) phase is
Macromolecules: A Comprehensive Guide to Polymers
Macromolecules
Contents
Polymers, also known as macromolecules, are large molecules with high molecular masses, reaching millions of atomic mass units (amu). They are formed by the repetition of smaller units called monomers, linked together by covalent bonds.
Polymer chains interact with each other through van der Waals forces, hydrogen bonding, or hydrophobic interactions.
Classification of Polymers
Polymers can be classified based on several criteria:
Origin
- Natural polymers: Rubber, polysaccharides
Sustainable Food Waste Management and Waste Minimization Techniques
Applications for Food Waste Management
What is Food Waste?
Food waste is a global issue with significant environmental and economic consequences. It encompasses discarded food that could have been consumed by humans or animals. This document explores various sustainable food waste management (SFM) techniques, including:
Composting
Composting decomposes food waste into nutrient-rich soil amendments. Different methods, such as backyard composting and vermicomposting, are employed.
Anaerobic Digestion
Anaerobic
Basic Chemistry Concepts
Atoms and Subatomic Particles
Atom: The smallest unit of an element that retains the element’s properties. Nucleus: The dense core of an atom, containing protons and neutrons, and holding most of the atom’s mass. Proton: A positively charged subatomic particle found in the nucleus with a mass of 1 atomic mass unit (amu). Neutron: A neutral subatomic particle found in the nucleus with a mass of 1 amu. Electron: A negatively charged subatomic particle found outside the nucleus with negligible mass.
Read MoreScience Class Notes: Chemistry, Physics & Biology
Lesson 1: Atoms, Elements, Properties & Changes
Atoms & Elements
Atom: The smallest unit of matter. Example: Oxygen atom (O)
Element: A pure substance made up of only one type of atom. Example: Carbon (C)
Properties of Matter
Physical properties: Characteristics observed without changing the substance. Example: Color, density, melting point.
Chemical properties: Characteristics that describe how a substance reacts with others. Example: Reactivity, flammability.
Changes in Matter
Physical change:
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